microsoft/semantic-kernel · error · Exception

Payload parameters cannot be retrieved from the `{operation.

Error message

Payload parameters cannot be retrieved from the `{operation.id}` operation payload metadata because it is missing.

What it means

When `get_payload_parameters` is called with `use_parameters_from_metadata=True`, it expects the operation to have a `request_body` defined (from the OpenAPI spec). If `operation.request_body` is None — meaning the spec declared no request body for this operation — this generic Exception is raised. It signals a mismatch: the caller asked for payload-parameter extraction from metadata, but there is no payload metadata to extract from.

Source

Thrown at python/semantic_kernel/connectors/openapi_plugin/models/rest_api_operation.py:500

            else:
                # Handle property.properties as a single instance or a list
                if isinstance(property.properties, RestApiPayloadProperty):
                    nested_properties = [property.properties]
                else:
                    nested_properties = property.properties

                parameters.extend(
                    self._get_parameters_from_payload_metadata(nested_properties, enable_namespacing, parameter_name)
                )
        return parameters

    def get_payload_parameters(
        self, operation: "RestApiOperation", use_parameters_from_metadata: bool, enable_namespacing: bool
    ):
        """Get the payload parameters for the operation."""
        if use_parameters_from_metadata:
            if operation.request_body is None:
                raise Exception(
                    f"Payload parameters cannot be retrieved from the `{operation.id}` "
                    f"operation payload metadata because it is missing."
                )
            if operation.request_body.media_type == RestApiOperation.MEDIA_TYPE_TEXT_PLAIN:
                return [self.create_payload_artificial_parameter(operation)]

            return self._get_parameters_from_payload_metadata(operation.request_body.properties, enable_namespacing)

        return [
            self.create_payload_artificial_parameter(operation),
            self.create_content_type_artificial_parameter(),
        ]

    def get_default_response(
        self, responses: dict[str, RestApiExpectedResponse], preferred_responses: list[str]
    ) -> RestApiExpectedResponse | None:
        """Get the default response for the operation.

View on GitHub (pinned to c028a0c7dc)

Solutions

1. Set `use_parameters_from_metadata=False` for operations that have no request body, so a synthetic payload parameter is used instead.
2. Add a request body to the operation in the OpenAPI spec if one is expected.
3. Filter or skip operations without request bodies when iterating with metadata-based payload extraction enabled.

Example fix

// before
runner = OpenAPIFunctionRunner(use_parameters_from_metadata=True)
# applied to a GET operation with no body -> raises
// after
runner = OpenAPIFunctionRunner(use_parameters_from_metadata=False)
# or only enable metadata extraction for operations that have a request body

def has_request_body(operation) -> bool:
    return operation.request_body is not None

def operation_has_payload(operation: 'RestApiOperation') -> bool:
    """Return True if the operation has request body metadata for payload extraction."""
    return operation.request_body is not None

try:
    params = builder.get_payload_parameters(operation, use_parameters_from_metadata=True, enable_namespacing=True)
except Exception as e:
    if "payload metadata" in str(e) and "missing" in str(e):
        # fall back to use_parameters_from_metadata=False for this operation
        params = builder.get_payload_parameters(operation, use_parameters_from_metadata=False, enable_namespacing=True)

When it happens

Trigger: Calling an OpenAPI operation function with `use_parameters_from_metadata=True` (or the runner defaulting to it) for an operation that has no request body defined in the OpenAPI spec. The operation is a GET or DELETE with no body, but payload metadata extraction was requested.

Common situations: The OpenAPI runner is configured to extract payload parameters from metadata globally, but some operations (GET, DELETE) have no request body. A spec was modified to remove a request body but the runner configuration was not updated. Note: this raises a bare `Exception` (not FunctionExecutionException), which is a code-quality concern.

Related errors

• The `RestApiOperation` instance with id {self.id} is frozen
• No argument is provided for the `{parameter.name}` required
• Error building the URL for the operation {self.id}: {e!s}
• The operation path resolves to '{request.scheme}://{request.
• The operation path resolves to '{request.path}', which is ou

AI-assisted analysis of microsoft/semantic-kernel@c028a0c7dc (2026-08-13). Data as JSON: /api/errors/957ae9f3a3c6a579. Report an issue: GitHub.